"""
Copyright 2024-2026 ReplyPier

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

The client's IP for keying (rate limits, telling visitors apart). Our nginx
APPENDS the real client IP to any X-Forwarded-For the client sent, so only
the RIGHTMOST entry is trustworthy - the first one can be anything.
"""

from fastapi import Request


def forwarded_client_ip(request: Request) -> str:
    forwarded = request.headers.get("x-forwarded-for")
    if forwarded:
        return forwarded.split(",")[-1].strip()
    return request.client.host if request.client else "unknown"